From owner-chemistry@ccl.net Sat Oct 3 21:34:00 2015 From: "janl|,|speakeasy.net" To: CCL Subject: CCL: Sending email to ccl.net gets harder Message-Id: <-51802-151003213135-7737-Zz2+DD/j6v2zc6yfB9FlTg^server.ccl.net> X-Original-From: janl%speakeasy.net Content-Disposition: inline Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=UTF-8 Date: Sat, 03 Oct 2015 21:31:10 -0400 MIME-Version: 1.0 Sent to CCL by: janl[#]speakeasy.net Dear members of Computational Chemistry List, I placed another restriction on email to ccl.net. The IP address from which the connection to port 25 on server.ccl.net is attempted will need to resolve both ways, that is: nslookup 66.93.212.15 Server:         64.81.159.2 Address:        64.81.159.2#53 Non-authoritative answer: 15.212.93.66.in-addr.arpa       name = server.ccl.net. nslookup server.ccl.net Server:         64.81.159.2 Address:        64.81.159.2#53 Non-authoritative answer: Name:   server.ccl.net Address: 66.93.212.15 The outgoing mail server IP address has to resolve to the fully qualified domain name, and this fully qualified domain name has to resolve on the DNS server to the IP address of the mail server. Professionally managed email gateways have this set up well, but spammers use open email relays on misconfigured machines and the reverse lookups do not resolve. Of course, they also use legitimate email accounts to which they got access and this method will not help in such cases. If your email bounces from chemistry**ccl.net with the error: Oct  3 20:55:59 server sendmail[5926]: ruleset=check_relay, arg1=[219.238.144.201], arg2=219.238.144.201, relay=[219.238.144.201], reject=451 4.1.8 Client IP address 219.238.144.201 does not resolve talk to your email gurus/administrators... In the meantime, you can always send mail to chemistry**ccl.net using the Web interface at:Remember to select CCL Subscribers. To send email to me personally use link: https://server.ccl.net/cgi-bin/ccl/send_message_to_jan1 CCL gets over 10,000 spam attempts a day and it is not possible to review this stuff. It needs to be killed by the system.  Sorry for the inconvenience that it may cause... Jan Labanowski jkl**ccl.net